For a two-cycle or four-cycle internal combustion engine, in operation, air is introduced to the fuel for proper combustion. A motorcycle, snowmobile, or other motorized vehicle having a fuel injection or carburetion system, includes appropriate ducting to introduce air into the fuel to create an adequate air/fuel mixture for combustion. A conventional motorcycle, as shown in FIG. 1, includes an air breather 110 which provides air for the fuel combustion. The air breather 110 provides the sole intake of air into the fuel system of the engine. Note a cover plate 120 is conventionally provided on a motorcycle, which covers the crank pulley and crank shaft for the engine. There are bolts 130 provided for securing the cover plate 120 to the motorcycle. A filter may also be located within the air breather assembly.
To improve performance of the engine, including providing additional torque, horsepower, or other enhancements, modifications or additions can be provided for an engine. For example, for increasing the pressure (psi or “boost”) of air distributed into the fuel system to enhance performance, a supercharger may be provided. A supercharger (or “blower” as known in the art) forces more air and fuel into the cylinders of the engine. One current technique for integrating a supercharger into a motorcycle engine is to provide a purely gear-driven assembly that interconnects directly to the motor. This requires extensive integration within the motor and a significant amount of time and cost, generally at a specialized shop to install the supercharger and associated gearing assembly. In a conventional implementation, such a purely geared assembly typically requires a large number of gears, increasing the cost as well as increasing the chances of malfunction. This setup also employs the same lubrication system as the engine itself which increases the chance of oil loss and increases the complexity of the lubrication system. Gears are notoriously unforgiving of sudden impulses or acceleration. This increases the likelihood of a snapped shaft, gear tooth, or other component during operation. Accordingly, a severe disadvantage of this integrated type of purely geared system is that if or when it breaks, the entire engine is also destroyed.
The purely geared drive assembly is also not readily adjustable once integrated into a motor without having to modify the internal gears and integration within the motor. This disadvantageously fixes the amount of boost or air flow that is directed into the fuel system of the internal combustion engine to create the air/fuel mixture. Moreover, such a system requires extensive and continual repairs and down time, where a user cannot enjoy the motorcycle, each instance a change is desired. These systems also typically are most efficient at very high RPMs, which makes it impractical for efficient use at low and midrange RPMs.
Moreover, most available small-vehicle/motorcycle superchargers are an impeller/turbine type. These units generate significantly less boost than the popular roots rotor design. However, a roots supercharger has a form-factor that limits its use on a motorcycle, since in its normal orientation, the rotor axes are horizontal to interconnect with a parallel crankshaft via a belt or gears. All these challenges render the reliable supercharging of a motorcycle or other riding vehicle somewhat problematic.
It is desirable to avoid these and other disadvantages by providing a modular, self-contained, externally mounted supercharger drive assembly.